aabb_slab.h

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/** @file
 *  @author Bram de Greve (bram@cocamware.com)
 *  @author Tom De Muer (tom@cocamware.com)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2011 the Initial Developer.
 *  All Rights Reserved.
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 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
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 *  deleting the provisions above and replace them with the notice and other 
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 *  *** END LICENSE INFORMATION ***
 */
 
#ifndef LASS_GUARDIAN_OF_INCLUSION_PRIM_IMPL_AABB_SLAB_H
#define LASS_GUARDIAN_OF_INCLUSION_PRIM_IMPL_AABB_SLAB_H
 
#include "../prim_common.h"
#include "../../num/floating_point_consistency.h"
 
namespace lass
{
namespace prim
{
namespace impl
{
 
 
 
/** @internal
 */
template <typename T> inline
bool intersectSlab(const T min, const T max, const T support, const T direction, const T invDirection, T& tNear, T& tFar)
{
    if (direction == 0)
    {
        return support >= min && support <= max;
    }
    
    const T tMin = (min - support) * invDirection;
    const T tMax = (max - support) * invDirection;
    if (direction > 0)
    {
        if (tMin > tNear)
        {
            tNear = tMin;
        }
        if (tMax < tFar)
        {
            tFar = tMax;
        }
    }
    else
    {
        if (tMax > tNear)
        {
            tNear = tMax;
        }
        if (tMin < tFar)
        {
            tFar = tMin;
        }
    }
    return tNear <= tFar;
}
 
 
 
/** @internal
 */
template <typename T> inline
bool intersectSlab(const T min, const T max, const T support, const T direction, T& tNear, T& tFar)
{
    const T invDirection = num::inv(direction);
    return intersectSlab(min, max, support, direction, invDirection, tNear, tFar);
}
 
}
 
}
 
}
 
#endif
 
// EOF